#define  _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>

#include <stdio.h>
#include <string.h>

int main()
{
	int count = 0;
	char tmp[128] = { 0 };
	char arr[500] = { 0 };
	gets(arr);
	int len = strlen(arr);
	for (int i = 0; i < len; i++)
	{
		if (tmp[(int)arr[i]] == 0)
		{
			count++;
			tmp[(int)arr[i]] = 1;
		}
	}
	printf("%d\n", count);

	return 0;
}


int majorityElement(int* nums, int numsSize) {
	int count = 0;
	int countobj = nums[0];
	for (int i = 0; i < numsSize; i++)
	{
		if (countobj == nums[i])
		{
			count++;
		}
		else
		{
			count--;
			if (count < 0)
			{
				count = 1;
				countobj = nums[i];
			}
		}
	}

	return countobj;
}